As China makes last minute preparations to host the Olympics, the environment is proving to be one major wild card that Chinese leaders cannot totally control.  Olympic host city Beijing has some of the most polluted air in the world.  Despite measures aimed at clearing the skies, the air is still often a disturbing murky gray.  Stephanie Ho reports from the Chinese capital.

Cars fill road in center of Beijing on smoggy day, 04 Aug 2008

These days, people watch the skies above Beijing closely.  Some days, especially after it rains, the skies are relatively clear.

More often than not, though, a thick murky haze fills the air and makes it nearly impossible to see nearby buildings.

What is causing Beijing's gray skies?  Is it natural phenomena, or is it pollution?

The city's notoriously polluted air is one of the biggest question marks hanging over the Olympic games, which begin August 8.  China hopes the event will dazzle the world.  Will smoggy skies overshadow the party?

The Australian Olympic Committee's Peter Montgomery says the air pollution concerns him and his team.

"For us, the athletes' attitude to the event is paramount," he said.  If they don't want to compete, fine.  They will be absolutely under no pressure to compete if they feel uneasy or do not want to compete."

Some Olympic delegations, including the U.S. Olympic Committee, are making protective masks available to their athletes.

Beijing Municipal Environmental Protection Bureau spokesman Du Shaozhong says his office has worked "very hard" to ensure the air quality.

Du says there is no need to wear a face mask when participating in the games.  He says if the athletes insist on doing so, it will only end up an extra item in their luggage and make their luggage heavier.

Some of Beijing's more drastic pollution control measures include pulling half the city's more than three million cars off the roads and halting most construction.

Authorities also have shut polluting factories in and around the city.

Despite these restrictions, the Beijing air continues to be a soupy mix of harmful chemicals, particulate matter and water vapor.

The environmental group Greenpeace praises Beijing for making some improvements, but urges China to make long term policy decisions to deal with issues like air pollution.  Lo Sze Ping is with Greenpeace.

"Greenpeace believes that with the current performance of air quality in Beijing, the IOC, the Beijing Olympic Organization Committee, and also sports teams from various countries, have reason to be concerned with situation," he said.

Chinese officials acknowledge the air quality is sometimes not always as good as it should be, and warn that at times, it is "unhealthy for sensitive groups."  For the Olympics, though, they unswervingly promise to provide "good quality air" that they say "will not effect the health of the athletes."  
 
The Chinese government says it will impose even stricter pollution controls if the air quality fails to meet approved standards, once the games begin.

China has been having more success in taming nature in the coastal city of Qingdao, where algae blooms have
threatened the Olympic sailing venue.  Many experts say the blue-green
seaweed is caused by severe pollution from industrial sources, farm chemicals and domestic sewage.

Zang Aimin is with the Beijing Olympic Organizing Committee.

Zang says the workers have one important goal - to guarantee that 50 square kilometers of ocean is cleared for training and competition.

The algae blossomed in the waters around Qingdao in June.  Hundreds of boats and thousands of people have been mobilized to clean it up.  The Olympic sailing events are due to start August 9.